Chain conveyor and coupler link for same

ABSTRACT

A conveyor chain includes a first link, a second link, and a coupler link. The first link includes a first sprocket-engaging portion and a second sprocket-engaging portion, each protruding laterally away from one another. The second link includes a first sprocket-engaging portion and a second sprocket-engaging portion, each protruding laterally away from one another. The coupler link couples the first link to the second link, and the coupler link is positioned laterally between the first sprocket-engaging portion and the second sprocket-engaging portion of each link. The coupler link includes a first joint pivotably coupled to the first link and a second joint pivotably coupled to the second link. The first joint permits pivoting movement of the first link about a plurality of axes, and the second joint permits pivoting movement of the second link about a plurality of axes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of prior-filed, U.S. ProvisionalPatent Application No. 62/467,761, filed Mar. 6, 2017; U.S. ProvisionalPatent Application No. 62/467,766, filed Mar. 6, 2017; U.S. ProvisionalPatent Application No. 62/467,767, filed Mar. 6, 2017; U.S. ProvisionalPatent Application No. 62/467,769, filed Mar. 6, 2017; U.S. ProvisionalPatent Application No. 62/467,770, filed Mar. 6, 2017; and U.S.Provisional Patent Application No. 62/467,773, filed Mar. 6, 2017. Theentire contents of each of these documents are incorporated by referenceherein.

BACKGROUND

The present disclosure relates to material conveyors, and particularlyto chain and flight conveyors.

SUMMARY

Mining machines such as continuous miners and chain haulage units mayinclude chain conveyors that are capable of deflecting laterally inorder to travel through lateral turns. The chain conveyors may includeflight members for pushing or urging material along a pan. The chain maybe driven by one or more sprockets.

In one independent aspect, a conveyor chain includes a first link, asecond link, and a coupler link. The first link includes a firstsprocket-engaging portion and a second sprocket-engaging portion, thefirst sprocket-engaging portion and the second sprocket-engaging portioneach protruding laterally away from one another. The second linkincludes a first sprocket-engaging portion and a secondsprocket-engaging portion, the first sprocket-engaging portion and thesecond sprocket-engaging portion of the second link each protrudinglaterally away from one another. The coupler link couples the first linkto the second link, and the coupler link is positioned laterally betweenthe first sprocket-engaging portion and the second sprocket-engagingportion of each link. The coupler link defines a first joint pivotablycoupled to the first link and a second joint pivotably coupled to thesecond link. The first joint permits pivoting movement of the first linkabout a plurality of axes, and the second joint permits pivotingmovement of the second link about a plurality of axes.

In another independent aspect, a coupler link is provided for a conveyorchain including a first link and a second link. The coupler linkincludes a first end, a second end, a first leg extending between thefirst end and the second end, a second leg extending between the firstend and the second end, parallel to the first leg, a first bearing, anda second bearing. The first bearing is positioned adjacent the first endand supports a first pin for pivoting movement about a plurality of axesrelative to the first end. The first pin is configured to be coupled tothe first link. The second bearing is positioned adjacent the second endand supports a second pin for pivoting movement about a plurality ofaxes relative to the second end. The second pin configured to be coupledto the second link.

In yet another independent aspect, a coupler link is provided for aconveyor chain including a first link and a second link. The couplerlink includes a first end, a second end, a first leg extending betweenthe first end and the second end, a second leg extending between thefirst end and the second end, parallel to the first leg, and a gussetconnecting the first leg and the second leg and positioned between thefirst end and the second end. The gusset is oriented at an oblique anglerelative to a longitudinal axis extending between the first end and thesecond end.

In still another independent aspect, a conveyor chain includes a firstlink, a second link, and a coupler link. The first link includes a firstsprocket-engaging portion and a second sprocket-engaging portion, andthe first sprocket-engaging portion and the second sprocket-engagingportion each protrude laterally away from one another. The first linkfurther includes at least one first end surface. The second linkincludes a first sprocket-engaging portion and a secondsprocket-engaging portion, and the first sprocket-engaging portion andthe second sprocket-engaging portion of the second link each protrudelaterally away from one another. The second link further includes atleast one second end surface. The coupler link is positioned laterallybetween the first sprocket-engaging portion and the secondsprocket-engaging portion of each link. The coupler link includes afirst joint pivotably coupled to the first link and a second jointpivotably coupled to the second link. One of the at least one second endsurface contacts one of the at least one first end surface when at leastone of the first link and the second link pivots through a predeterminedangle.

Other aspects will become apparent by consideration of the detaileddescription and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mining machine with a portion of agathering head cutaway.

FIG. 2 is a perspective view of a forward end of the mining machine ofFIG. 1.

FIG. 3 is an exploded view of a conveyor drive assembly.

FIG. 4 is a perspective view of a chain conveyor unit.

FIG. 5 is an exploded view of the chain conveyor unit of FIG. 4.

FIG. 6 is a perspective view of a swivel link.

FIG. 7 is a section view of the swivel link of FIG. 6 viewed alongsection 7-7.

FIG. 8 is a section view of a portion of a chain conveyor unit of FIG. 4viewed along section 8-8.

FIG. 9 is a plan view of a portion of the chain conveyor unit of FIG. 4.

FIG. 10 is a perspective view of a swivel link including solidlubricant.

FIG. 11 is a side view of the swivel link of FIG. 10.

FIG. 12 is a section view of the swivel link of FIG. 10, viewed alongsection 12-12.

FIG. 13 is a perspective view of a chain conveyor unit according toanother embodiment.

FIG. 14 is an exploded view of the chain conveyor unit of FIG. 13.

Before any independent embodiments of the disclosure is explained indetail, it is to be understood that the disclosure is not limited in itsapplication to the details of the construction and the arrangements ofcomponents set forth in the following description or illustrated in thedrawings. The disclosure is capable of other independent embodiments andof being practiced or being carried out in various ways.

Also, it is to be understood that the phraseology and terminology usedherein is for the purpose of description and should not be regarded aslimiting. The use of “including,” “comprising” or “having” andvariations thereof herein is meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Theterms “mounted,” “connected” and “coupled” are used broadly andencompass both direct and indirect mounting, connecting and coupling.Further, “connected” and “coupled” are not restricted to physical ormechanical connections or couplings, and can include electrical or fluidconnections or couplings, whether direct or indirect. Also, electroniccommunications and notifications may be performed using any known meansincluding direct connections, wireless connections, etc.

DETAILED DESCRIPTION

FIG. 1 illustrates a mining machine 10, such as a continuous miningmachine. In the illustrated embodiment, the mining machine 10 includes aframe or chassis 18, a boom 22 pivotably coupled to the chassis 18, anda cutter head 26 supported on the boom 22. The chassis 18 may besupported for movement relative to a support surface (not shown) by atraction mechanism (e.g., crawlers 30).

As shown in FIGS. 1 and 2, a collecting mechanism or gathering head 34is positioned adjacent a first end or forward end 38 of the chassis 18,and a conveyor 42 extends in a continuous loop from the forward end 38of the chassis 18 toward a second or rear end 46 of the chassis 18. Thegathering head 34 is positioned below the cutter head 26 and includes adeck 50 and a pair of rotating arms 54 that engage and direct dislodgedmaterial onto the conveyor 42. The conveyor 42 transports the cutmaterial from the forward end 38 toward the rear end 46 (FIG. 1) of thechassis 18, from the area below the cutter head 26 to another conveyoror a haulage machine (not shown) positioned proximate the rear end 46 ofthe chassis 18.

As shown in FIG. 2, the conveyor 42 is a chain conveyor formed by chainlink connected sequentially in a continuous loop. The conveyor 42 drivescut material along a chain pan or deck 58. The conveyor 42 is driven bya drive assembly including a shaft 62 positioned adjacent the gatheringhead 34 of the chassis 18. As shown in FIG. 3, the shaft 62 is orientedlaterally relative to the chassis 18 (FIG. 2) and is driven (e.g., byone or more motors) to rotate relative to the chassis 18. A pair ofsprockets 66 engage and move the conveyor 42. In the illustratedembodiment, each sprocket 66 includes four teeth or lobes 70 spacedapart about the shaft 62, and recesses between the lobes 70 receive anddrive the conveyor 42.

FIGS. 4 and 5 show a unit of the chain 82 that forms the conveyor 42. Inthe illustrated embodiment, the chain 82 includes a first link or flightlink 86, a second link or connecting link 90, a coupler link or swivellink 94 coupling the flight link 86 to the connecting link 90, andflights or flight bars 98 positioned laterally outward from the flightlink 86. Another swivel link 94 may couple the connecting link 90 toanother flight link (not shown), and the conveyor chain 82 may thereforeinclude a sequence of alternating flight links and connecting links,each joined to one another by swivel links. In other embodiments, thechain 82 may include a different sequence of links—for example, multipleconnecting links may be positioned between one flight link and thesubsequent flight link. Various permutations of the link sequence arepossible.

In the illustrated embodiment, the flight link 86 includes a pair oflugs or side portions 106 (a first side portion 106 a and a second sideportion 106 b) and a bridge 110 extending between inner surfaces of theside portions 106. Each side portion 106 includes a pair of apertures114 extending through the inner surface and an outer surface of eachside portion 106.

As best shown in FIG. 5, the flight link 86 further includes a pair offlight pins 122, and each flight pin 122 extends outwardly from theouter surface of one of the side portions 106. In the illustratedembodiment, the flight pins 122 are aligned with one another (i.e.,along a common axis), and each of the flight pins 122 is positionedbetween the chain pins 222 (described in further detail below). Statedanother way, the flight pins 122 extend laterally or transverselyrelative to a direction of travel 126 of the conveyor 42. Each of theflight pins 122 is positioned between the apertures 114 of theassociated side portion 160. In the illustrated embodiment, each flightbar 98 is removably coupled to one of the flight pins 122 (e.g., by athreaded bolt 130 and nut 134). A sprocket-engaging portion or driveportion 138 of each flight pin 122 is positioned between the sideportion 106 and the associated flight bar 98. In the illustratedembodiment, an end portion 142 of each flight pin 122 is positionedwithin an opening 146 of one of the flight bars 98.

As shown in FIG. 5, each connecting link 90 includes a pair of lugs orside portions 170 (a first side portion 170 a and a second side portion170 b) and a bridge 174 extending between inner surfaces of the sideportions 170. Each side portion 170 includes a pair of apertures 178extending through the inner surface and an outer surface of each sideportion 170. In addition, a drive pin 182 extends outwardly from anouter surface of each side portion 170. Stated another way, each drivepin 182 extends laterally or transversely relative to the direction oftravel 126 of the chain 82. Each drive pin 182 is positioned between theapertures 178 of the associated side portion 170. The sprockets 66 (FIG.3) engage the drive pins 182 and the drive portions 138 of the flightpins 122 to drive the chain 82. In the illustrated embodiment, thebridge 174 of the connecting link 90 includes an opening 186.

Referring now to FIGS. 5-7, the swivel link 94 includes a first end 190,a second end 194, and a pair of openings 198 extending laterally fromone side of the swivel link 94 to another opposite side of the swivellink 94. A swivel link longitudinal axis 200 extends between the firstend 190 and the second end 194. Under nominal operating conditions, theswivel link longitudinal axis 200 is aligned with the direction oftravel 126 (FIG. 5) of the chain 82. In the illustrated embodiment, theswivel link 94 is formed as a vertical open chain link in which theopenings 198 are separated by a gusset or reinforcement member 202. Thereinforcement member 202 extends between a first or upper wall 204 and asecond or lower wall 208 of the swivel link 94. Each swivel link 94further includes a pair of support members or bearings, such asspherical bearings 206. Each bearing 206 is positioned in a pocket 210(FIG. 5) formed in an associated one of the openings 198 of the swivellink 94.

As best shown in FIG. 8, the reinforcement member 202 is oriented at anoblique angle relative to the swivel link longitudinal axis 200. In theillustrated embodiment, the reinforcement member 202 is oriented in aplane forming an acute angle A relative to the swivel link longitudinalaxis 200. In some embodiments, the angle A is between approximately 40degrees and approximately 80 degrees. In some embodiments, the angle Ais between approximately 60 degrees and approximately 75 degrees. Insome embodiments, the angle A is approximately 70 degrees. Statedanother way, an edge of the reinforcement member 202 adjacent one sideof the swivel link 94 is positioned closer to the first end 190 than thesecond end 194, while an edge adjacent the other side of the swivel link94 is positioned closer to the second end 194 than the first end 190.

The reinforcement member 202 increases the strength and stiffness of theswivel link 94 between the upper wall 204 and the lower wall 208 (i.e.,in a vertical direction) and distributes stress between the upper wall204 and lower wall 208. The reinforcement also reduces sound resonance,resulting in a higher frequency and lower amplitude sound thanun-reinforced or open loop links.

Referring again to FIGS. 5 and 7, the swivel link 94 further includes apair of spherical bearings 206, with each bearing 206 positioned in oneof the openings 198. In the illustrated embodiment, each sphericalbearings 206 is formed as a spherical bushing including a sphericalouter surface 250 (FIG. 12) and a cylindrical inner surface 254 forreceiving the chain pins 214, 222. Each opening 198 of the swivel link94 includes a spherical recess 210 (FIGS. 6 and 7) receiving one of thespherical bearings 206. Due to the angled orientation of thereinforcement member 202, one spherical bearing 206 may be inserted intoa respective opening 198 from each side of the swivel link 94. Inaddition to permitting spherical movement of the spherical bearings 206,the spherical recesses 210 reduce the contact stress in the swivel link94 and increase the service life of the swivel link 94. The sphericalrecesses 210 permit the swivel link 94 to be formed as a unitary orsingle piece, significantly increasing the load capacity of the chain82.

As shown in FIG. 5, one of the openings 198 is aligned with parallelapertures 178 in the side portions 170 of the connecting link 90, whilethe other opening 198 is aligned with parallel apertures 114 in the sideportions 106 of the flight link 86. A first connecting pin or firstchain pin 214 is inserted through the apertures 178 of the connectinglink side portions 170 and through one opening 198 of the swivel link94, thereby coupling the swivel link 94 to the connecting link 90.Similarly, a second connecting pin or second chain pin 222 is insertedthrough the apertures 114 of the flight link side portions 106 andthrough the other opening 198 of the swivel link 94, thereby couplingthe swivel link 94 to the flight link 86. Each of the chain pins 214,222 is supported for pivoting movement relative to the swivel link 94 byone of the bearings 206 positioned in the connected swivel link 94.

In addition, in the illustrated embodiment, the first chain pin 214 isinserted through the connecting link side portions 170 in a firstlateral direction, while the second chain pin 222 is inserted throughthe flight link side portions 106 in a second lateral direction oppositethe first lateral direction. The chain pins 214, 222 are secured againstmovement relative to the connecting link 90 and the flight link 86 byretainers (e.g., self-locking retaining rings—not shown). Also, in someembodiments, an outer side of one of the side portions 170 may includean aperture 178 b having a reduced diameter; as a result, each pin 214can only be inserted from one side of the connecting link 90 to theother. The flight pin apertures 114 may be structured in a similarmanner.

As shown in FIGS. 7 and 8, each chain pin 214, 222 is supported forpivoting movement relative to the swivel link 94 by one of the sphericalbearings 206. Unlike conventional chains, the swivel link 94 providesmultiple points of lateral articulation. The lateral pivot angle issplit or distributed between separate joints, thereby reducing the rangeof movement for each joint and reducing the wear on the interfacesbetween the moving parts. Furthermore, as shown in FIG. 8, the ends ofthe side portions 170 of the connecting link 90 include limit surfaces230 b that contact corresponding limit surfaces 230 a on an adjacentlink (e.g., a flight link 86) to prevent hyperextension of the chain 82and prevent contact between the connecting link 90 and the swivel link94. The limit surfaces 230 permit the desired articulation, but reducestress between connected links 90, 94 during a contact condition.Although FIG. 8 illustrates a flight link 86 and a connecting link 90connected by a swivel link 94, it is understood that the swivel link 94may connect a connecting link 90 and another connecting link 90, andsimilar limit surfaces 230 may be integrated onto the side portions ofeach link.

Also, as shown in FIG. 9, each lateral or side surface of each end ofthe swivel link 94 includes a convex curved profile 238 that is shorterthan a width of the pocket defined between the two side portions 170.The curved outer profile of the side surface 238 permits the swivel link94 to articulate relative to the connecting link 90, but limits lateraltranslational movement of the swivel link 94 relative to the connectinglink 90. In conventional chains, clearance between the links, althoughnecessary to permit articulation, may also allow axial movement of thelink and result in uneven loading and wear on pins connecting the links.The convex outer profile 238 on the lateral surfaces of the swivel link94 limits translational movement to keep the swivel link 94substantially centered relative to adjacent flight links 86 andconnecting links 90.

FIGS. 10-12 illustrates a swivel link 94 according to one embodiment.The swivel link 94 includes solid oil 450 filling the void or spacebetween the walls 204, 208 of the swivel link 94 and between eachspherical bearing 206 and the reinforcement member 202. The solid oil450 may be initially in a liquid state when it is applied to the swivellink 94 before solidifying. The solid oil 450 may fill minor surfaceaberrations to reduce friction. The solid oil 450 may provide solidprotection against corrosion while in storage and/or transit, and alsoprovides continuous integral lubrication between chain components duringoperation. The solid oil 450 also reduces the amount of contaminantspermitted to penetrate into interfaces between adjacent chaincomponents.

FIGS. 13 and 14 illustrate a chain 882 according to another embodiment.Features of the chain 882 are similar to features of the chain 82 andare identified with similar reference numbers, plus 800. At least somedifferences and/or at least some similarities between the chain 82 and882 are described below. In addition, components or features describedwith respect to only one or some of the embodiments described herein areequally applicable to any other embodiments described herein.

The chain 882 includes a flight link 886 including a pair of sideportions 906 that are separate from one another and not directlyconnected. Stated another way, the flight link 886 does not include abridge between the side portions 906. Rather, the side portions 906 arecoupled to one another by the connecting pins 1022 (FIG. 14) extendingbetween the side portion 906 and through a swivel link 894. Similarly, aconnecting link 890 includes a pair of side portions 970 that areseparate from one another and not directly connected. Stated anotherway, the connecting link 886 does not include a bridge between the sideportions 970, which are formed as separate components 970 a, 970 b.Rather, the side portions 970 are coupled to one another by theconnecting pins 1014 (FIG. 14) extending between the side portion 970and through the swivel link 894.

In addition, a flight 898 is formed integrally with each side portion906 of the flight link 886. In the illustrated embodiment, a driveportion 938 protrudes from each side portion 906, and the flight 898extends laterally outwardly from an end of the drive portion 938. Thedrive portion 938 is positioned between the side portion 906 and theflight 898. It is understood that aspects of the chain 882 may beincorporated into other disclosed embodiments. For example, an integralflight may be incorporated into the flight link 86 described above withrespect to FIGS. 4 and 5.

Although the conveyor is described above with respect to a continuousmining machine, it is understood that the conveyor may be incorporatedinto other types of machines including but not limited to roadheadersand entry drivers, as well as loading and hauling machines including butnot limited to shuttle cars, battery haulers, or other types.

Although aspects have been described in detail with reference to certainpreferred embodiments, variations and modifications exist within thescope and spirit of one or more independent aspects as described.

What is claimed is:
 1. A conveyor chain comprising: a first linkincluding a first sprocket-engaging portion and a secondsprocket-engaging portion, the first sprocket-engaging portion and thesecond sprocket-engaging portion each protruding laterally away from oneanother; a second link including a first sprocket-engaging portion and asecond sprocket-engaging portion, the first sprocket-engaging portionand the second sprocket-engaging portion of the second link eachprotruding laterally away from one another; and a coupler link couplingthe first link to the second link, the coupler link including a firstend and a second end, the first end positioned laterally between thefirst sprocket-engaging portion and the second sprocket-engaging portionof each link, the coupler link further including a lateral opening and aconcave pocket, the lateral opening extending through the first end, theconcave pocket formed on an inner surface and extending around a portionof the lateral opening, the concave pocket having an at least partiallyspherical shape, the coupler link further including a bearing positionedin the pocket and having an outer spherical surface, the bearingsupporting a connecting pin extending through the lateral opening andengaging the first link, the bearing permitting pivoting movement of thefirst link about a plurality of axes.
 2. The conveyor chain of claim 1,wherein the lateral opening is a first lateral opening, the pocket is afirst pocket, and the bearing is a first bearing, wherein the couplerlink further includes a second lateral opening extending through thesecond end, a second concave pocket formed on an inner surface andextending around a portion of the lateral opening, the second pockethaving an at least partially spherical shape, the coupler link furtherincluding a second bearing positioned in the second pocket and having anouter spherical surface, the second bearing supporting a secondconnecting pin extending through the second lateral opening and engagingthe second link.
 3. The conveyor chain of claim 1, wherein a solidlubricant is positioned within at least one of the bearing and the spacewithin the coupler link extending around an outer portion of thebearing.
 4. The conveyor chain of claim 1, wherein the coupler linkincludes a first planar leg extending between the first end and thesecond end, and a second planar leg extending between the first end andthe second end, the second leg being parallel to the first leg, thecoupler link further including a gusset connecting the first leg and thesecond leg and positioned between the first end and the second end, thegusset oriented at an oblique angle relative to a longitudinal axisbetween the first end and the second end of the coupler link.
 5. Theconveyor chain of claim 1, wherein the coupler link includes a firstplanar leg extending between the first end and the second end, and asecond planar leg extending between the first end and the second end,the second leg being parallel to the first leg, the first leg and thesecond leg each including lateral edges having a curved profile topermit pivoting movement of the first link relative to the coupler link.6. A coupler link for a conveyor chain, the conveyor chain including afirst link and a second link, the coupler link comprising: a first end;a second end; a first leg extending between the first end and the secondend; a second leg extending between the first end and the second end,parallel to the first leg and spaced apart from the first leg to form aninterior space between the first end, the second end, the first leg, andthe second leg; a first concave pocket formed on inner surfaces of thefirst leg, the first end, and the second leg, the first pocket extendingaround a portion of the interior space, the first pocket having an atleast partially spherical shape; a second concave pocket formed on innersurfaces of the first leg, the second end, and the second leg, thesecond pocket extending around a portion of the interior space, thesecond pocket having an at least partially spherical shape; a firstbearing positioned in the first pocket and having a spherical outersurface, the first bearing supporting a first pin for pivoting movementabout a plurality of axes relative to the first end, the first pinconfigured to be coupled to the first link; and a second bearingpositioned in the second pocket and having a spherical outer surface,the second bearing supporting a second pin for pivoting movement about aplurality of axes relative to the second end, the second pin configuredto be coupled to the second link.
 7. The coupler link of claim 6,wherein a solid lubricant is positioned within at least one of the firstbearing and the second bearing.
 8. The coupler link of claim 6, whereina solid lubricant is positioned within at least one of a space extendingaround an outer portion of the first bearing and a second spaceextending around an outer portion of the second bearing.
 9. The couplerlink of claim 6, wherein a longitudinal axis extends between the firstend and the second end, the coupler link further including a gussetconnecting the first leg and the second leg and positioned between thefirst end and the second end, the gusset oriented at an oblique anglerelative to the longitudinal axis.
 10. The coupler link of claim 6,wherein the first leg and the second leg each include lateral edgeshaving a convex curved profile to permit pivoting movement of the firstlink relative to the coupler link while limiting lateral translationalmovement of the coupler link relative to the first link.
 11. A couplerlink for a conveyor chain, the conveyor chain including a first link anda second link, the coupler link comprising: a first end; a second end; afirst leg extending between the first end and the second end; a secondleg extending between the first end and the second end, parallel to thefirst leg; and a gusset connecting the first leg and the second leg andpositioned between the first end and the second end, the gusset having aplanar surface oriented perpendicularly relative to the first leg andthe second leg, the planar surface oriented at an oblique angle relativeto a longitudinal axis extending between the first end and the secondend.
 12. The coupler link of claim 11, the gusset partitioning aninternal space of the coupler link into a first portion proximate thefirst end and a second portion proximate the second end, the couplerlink further including a first spherical bearing positioned in the firstportion and a second spherical bearing positioned in the second portion.13. The coupler link of claim 12, wherein a solid lubricant ispositioned within at least one of the first spherical bearing and thesecond spherical bearing.
 14. The coupler link of claim 12, wherein asolid lubricant is positioned within at least one of a space extendingaround an outer portion of the first bearing and a second spaceextending around an outer portion of the second bearing.
 15. A conveyorchain comprising: a first link including a first sprocket-engagingportion and a second sprocket-engaging portion, the firstsprocket-engaging portion and the second sprocket-engaging portion eachprotruding laterally away from one another, the first link furtherincluding at least one first end surface; a second link including afirst sprocket-engaging portion and a second sprocket-engaging portion,the first sprocket-engaging portion and the second sprocket-engagingportion of the second link each protruding laterally away from oneanother, the second link further including at least one second endsurface; and a coupler link positioned laterally between the firstsprocket-engaging portion and the second sprocket-engaging portion ofeach link, the coupler link including a first end and a second end, anda lateral opening extending through the first end, a concave pocketformed on an inner surface and extending around a portion of the lateralopening, the concave pocket having an at least partially sphericalshape, the coupler link further including a bearing positioned in thepocket and having an outer spherical surface, the bearing supporting aconnecting pin extending through the lateral opening and engaging thefirst link, the bearing permitting pivoting movement of the first linkabout a plurality of axes, wherein one of the at least one second endsurface contacts one of the at least one first end surface when at leastone of the first link and the second link pivots through a predeterminedangle.
 16. The conveyor chain of claim 15, wherein the first linkincludes a pair of parallel side portions and each side portion includesa first end surface, the first sprocket-engaging portion protruding froman outer surface of one of the side portions, the secondsprocket-engaging portion protruding from an outer surface of the otherof the side portions, wherein the second link includes a pair ofparallel side portions and each side portion includes a second endsurface, the first sprocket-engaging portion protruding from an outersurface of one of the side portions of the second link, the secondsprocket-engaging portion protruding from an outer surface of the otherof the side portions of the second link.
 17. The conveyor chain of claim16, wherein each first end surface is oriented at an oblique anglerelative to a direction of travel of the conveyor chain, wherein eachsecond end surface is oriented at an oblique angle relative to thedirection of travel of the conveyor chain.
 18. The conveyor chain ofclaim 15, wherein the first portion and the second portion of the firstlink are connected to one another by a bridge portion integrally formedwith the first portion and the second portion.
 19. The conveyor chain ofclaim 15, wherein the first portion and the second portion of the firstlink are separate from one another.